Conventionally, in a magnetic recording medium such as a hard disk, induction of a magnetic head to perform writing into the magnetic recording medium is performed by using a servo region provided in the magnetic recording medium.
Recently, as a method of writing into the magnetic recording medium, a heat-assisted recording method is proposed. In the heat-assisted recording method, emission light from a light source is converted into irradiation light by an irradiation unit and is irradiated to a part of a recording surface of the magnetic recording medium (magnetic disk), the magnetic recording medium is regionally heated, and writing control is performed magnetically with respect to the magnetic recording medium with decreased coercivity. As an example of the light source, there is a laser element. When the laser element is used, a laser beam is output as the output light. As an example of the irradiation unit, there is a near-field light element. When the near-field light element is used, near-field light is emitted as the irradiation light. By using the heat-assisted recording method, an improvement of a surface recording density is expected.
However, as the surface recording density is improved, a magnetic head may be deviated from a track when disturbance is generated.